Construction worker Jorge Julio López, who has testified against a man who was a senior official in the security forces while Argentina was under military rule, has not been seen since 17 September, when his family saw him at his home in the city of La Plata, Buenos Aires Province. There are fears that he may have been abducted by people connected with the former military government because of his involvement in the trial, and as a warning to potential witnesses in similar future trials.